Jennifer Lopez  stopped by The Tonight Show on Monday to hit the stage with Jimmy Fallon , joining him for a "Tight Pants" duet. In the past, Will Ferrell fought Fallon over tight pants , both wanting the style all to themselves. Lopez brought the same message and rocked the same hairstyle as Ferrell, but she paired her tight pants with a cropped turtleneck. Arguing that she should be the "only one" to sport the tightest pants in all the land, Lopez warned Fallon, "Don't make me take off my heels." Watch the pair's funny performance above.